Apparatus for refining used lubricating oil



Jan. 20, 1953 v c. F. MILLER ETA.

APPARATUS FOR REFINING USED LUBRICATING OIL Filed oct. 22, 194e 5 Sheets-Shea#l l lgl. 6

j 5y f2 i9 60 @um unl-qi), i

ffl l l1 mmm "uw www JY 2 Jan. 20, 1953 c. F. MULLER E'r-AL 2,626,229

' APPARATUS FOR REFINING USED LUBRICATING OIL Filed Oct. 22.. 1948 5 Sheets--Sheel 2 CD77@ M0701@ ./7 212101471@ ys.

Jan. 20, 1953 c. F. MILLER ETA. 4 2,625,229 APPARATUS FORl REFINING USED LUBRICATING OIL Filed Oct.- 22. 1948 5 Sheets-Sheet 5 L f E l l ""I 73 UWENTORS Jan. 20, 1953 c. F. MILLER ET Al.

APPARATUS FOR REFINING USED LUBRICATING OIL Filed oct. 22. 194s 5 Sheets-Sheet 4 INVENToRs W Mo( waging/'5.

Jan. 20, E953 c. F. MILLER ETAL 125,229

APPARATUS FOR REFINING USED LUBRICATING OIL Patented Jan. 20, :195.3

OFFICE APPARATUS' FOR REFINING USED v. LUBRICATING OIL Carl F. Miller and Albert Miller, Orchard Park, N. Y.

Application October 22, 1948, Serial No. 55,926

(Cl. l96-l6I 5 Claims. l

^ This invention relates to apparatus for refining used lubricating oil and more particularly to the agitation of theoil being reiined and to the autoina'gtic electrical control of the full sequence of operation so that the operator is relieved from the necessity of supervising the operation after starting the refining sequence.

The invention is directed to apparatus designed to :refine used lubricating oil which usually contains not only particles of metal, dirt and discoloring matter but also lighter fractions of gasoline. kerosene, acids, water or the like all of which must'be removed to restore the lubricating oil to its original condition. The present invention is directed to apparatus in which a charge of the used oil is preheated through heat derived from the outgoing charge of refined oil and is admitted, together with a charge of` refining solids, such as fullers earth which acts to bleach, neutralize acids and absorb impurities and discoloring matter, into a distillation chamber. In this distillation chamber the charges of used lubricating Uoil and refining solids are heated to a temperature to vaporize the lighter fractions which are jdrawn off by an exhaust fan. After the predetermined distillation temperature is reached the chargesof lubricating oil and refining solids are'transferred to a filteringchamber where these charges are passed through a filter paper to remove the rening-solids andA remaining impurib..

ties; the filtration being under vacuum. After the iinished oil has been brought into heat exchange relation with an incoming charge of used lubricating oilit is withdrawn from the apparatus.

' The present invention is directed to an improved means for agitating the charges of used lubricating oil and rening solids whilebeing distilled ,andi tov the electrical control'for4 automatically *effecting a complete" sequencev of operation 'ifiresponse tothe closing of va start-switch by the operator.

'Accordingly one of the principal objects of the invention is to provide for the simple and effec- '-tive agitation of the oil and refining solids in the .'still, whichy agitation not only maintains the re- Vflning solids in suspensionand increases heat transfer between thewalls of the still and the oil .being distilled and increases the eiective con- Atact between the oil and the reiining solids but falso Aaerates the oil being distilledlO accelerateI thejrelease of. the lighter'fractions. I

Another object is.to provide a `simple, reliable, accurate and rugged electrical control-'for the refining sequence which insures .the heating ofthe used oil and refining solidsto'the proper 'distil- 2y lation temperature, the transfer of the distilled oil and rening solids to an 'overhead filtering chamber and the restoration of the electrical components to their original condition for a repetitionof the sequence of operation, Other objects and advantages will appear from the following description and drawings in which:

Fig. l is a side elevational view of apparatus for refining used lubricating oil and constructed in accordance with the pre-sent invention.

Fig. 2 is a top plan view thereof.

Fig. 3 is a top plan view similar to Fig. 2 Vshowing parts broken away to disclose parts of the operating mechanism.

Fig. e is a vertical section taken generally on line d-, Fig. 2.

Fig. 5 is a fragmentary enlarged vertical section taken generally on line 5--5, Fig. 2.

, Fig. 6 is a horizontal section taken generally on line 6 6, Fig. 4.

Fig. '7 is a horizontal section taken generally on line '1 -1, Fig. 4.

Fig. 8 is a fragmentary enlarged view similar to Fig. 5 and showing in greater detail the clamping t of the lter paper disk between the upper end head and cover of the apparatus'.

Fig. 9 is a wiring diagram illustrating the electric components and the electrial circuit of the apparatus.

The apparatus forming the subject of the present invention is particularly adapted for use by garages and the like in refining used lubricating oil in successive batches of several gallons or so and to this end the apparatus includes a circuv lar base plate II) mounted on casters or rollers l I so that the entire apparatus can be moved from place to place as conditions may require. A vertical central plate I2 is mounted on the .base plate Il] so as to extend 'diametric'ally from .one side thereof to the other and the vertical edges of this diametrically extending plate I2 are con#` plate I4 is preferably supported fromthe base.y plate I 0 by one or'more posts I5, two being shown.

For Y additional strength; a circular` band -I 6 -ex-` tends-around and is secured, as 4by welding, -to the "circular edge'of the semicircular'horizontal plate A semic'ircular, horizontal plate I4 isi I5 and upper extremity of the semicylindrical shell I3. The apparatus includes an upper cylindrical sheet metal outer shell I8, the lower part of which preferably curves inwardly as shown. On the corresponding side of the apparatus, the lower edge of this outer sheet metal shell E8 is shown as welded to that part of the circular band I5 secured to the semi-circular horizontal plate I d, and on the other side of the apparatus the lower edge of this outer sheet metal shell is shown as welded directly to the outer face of the semicylindrical sheet metal shell I3.

The upper extremity of this outer sheet metal shell I8 also preferably curves inwardly and has its edge suitably secured to an upper end head I3 which is preferably in the form of a casting and made of a relatively light weight aluminum alloy. An inner cylindrical sheet metal shell 25 is arranged within and in spaced relation to the outer cylindrical sheet metal shell I8 and has its upper edge suitably secured to the rim of the upper end head I9. The lower edge of this inner cylindrical sheet metal shell is joined to the margin of a frustoconical bottom 2I terminating in a horizontal circular central plate 22. The frustoconical bottom 2l, 22 is arranged immediately above the horizontal semicircular plate Iii and the inner cylindrical shell 20, together with its bottom and the upper end head I9 are preferably additionally supported by a plurality of L- shaped brackets 23 welded to the sides of the inner cylindrical sheet metal shell 20 and secured, as by bolts 24, to the horizontal semicircular plate I.

The inner shell 20, 2I, 22 is provided with a sump 25 which extends downwardly into the space defined by vertically diametrically extending plate I2 and the semicylindrical shell I3 and in spaced relation' thereto. This sump 25 is shown as comprising a cylindrical sheet metal shell 25 forming a distillation chamber 27,' the upper end of this shell 26 extending through an opening 23 through the corresponding side 'of' the frustoconical bottom 2I of the inner cylindrical shell 20 and being secured thereto in any suitable manner as by welding. The sump is provided with a circular bottom Wall 29 which encloses the same. It will therefore be seen that the apparatus as described generally includes an outer wall formed by the base plate I0, the diametrically extending vertical plate I2, the semicylindrical shell I3, the semicircular horizontal plate I4 and the outer cylindrical sheet metal shell I8 and an inner shell comprising the inner cylindrical sheet metal shell 20, its bottom 2|, 22 and its sump 25. The space between these inner and outer shells is lled with atsuoitably thermal insulating material indicated a 3 The charge of used lubricating oil is received in the distillation chamber 2'I of the sump 25 and.

is subjected therein to heat to drive 01T the lighter fractions, these lighter fractions escaping as vapor into the vapor chamber 3| formed by the inner cylindrical sheet metal shell 28' and its bottom 2|, 22 to be thence exhausted to the atmosphere, as hereinafter described. For the purpose of bringing the used lubricating oil contained within the sump 25 up to the proper distillation temperature, the sides of this sump are formed in part by an annular series of vertical hollow ns 32 projecting radially into'the sump and forming vertical recesses on the exterior of this sump. In each of these recesses is arranged an electrical heating element 34 of any suitable form, the arrangement of these. heating elements in these hollow radial fins of the sump 25 insuring a rapid rate of heat transfer to the batch of oil contained within this sump thereby to accelerate bringing each batch of oil to the desired distillation temperature.

The round upper end head I9 of the apparatus, which is preferably in the form of a light weight alloy casting, is formed to provide a sump or depending shell 35 which is disposed coaxially within the upper part of the inner cylindrical sheet metal shell 25 and which forms a chamber 36 for receiving the charge of oil after it has been refined or processed. |This rened oil receiving shell 35 is enclosed by a cylindrical shell 38 having a horizontal bottom 39 and the upper edge of which is suitably secured to the upper end head I9. The space I5 between the rened oil receiving shell 35 and this surrounding cylindrical shell 39 forms a preheating chamber for receiving the initial charge of used lubricating oil. To achieve heat transfer between the nished oil in the rened oil chamber 3S and the incoming charge of used lubricating oil in the preheating chamber 40, the cylindrical wall of the sump 35 is provided with ns I kprojecting radially into the preheating chamber 5D.

IThe rened oil chamber 36 receiving the nnished oil is enlarged at its upper end by the provision of the outwardly and upwardly enlarging face #l2 provided in the upper end head I9 and around the rim of this conical enlargement 42 of the chamber 25 the head I9 is provided with a circular' seat 43 in which the rim ofa supporting grid 44 is disposed. This grid can be of any suitable form to support a foraminous metal screen disk 55, the grid being shown as being in the form of a skeleton casting having suitable .circular and radial ribs to provide large openings 46 which the foraminous disk covers.

Immediately outside of the seat 43 for the grid 44 and the screen disk 45 the head I5 is formed to provide a seat 48 for a disk 59 of filter paper. In cross section this seat has a generally horizontal inner portion 50 and a frustoconical outer portion 5I of upwardly enlarging form. The margin of the filter paper 49 is irmly clamped against this outer upwardly enlarging frustoconical portion 5I by a circular dome shaped cover 52, this cover having a depending rim 53 for this purpose which conforms to the shape of the frustoconical outer part 5I of the filter paper seat 50.

This cover can be secured in tightly clamping and sealing relation with the lter paper 49 in any suitable manner, as by the bifurcated holddown bar 54 having handle bars 55 at its free end. The bifurcated ends of this holddown bar 5:1 are shown as pivoted, as at 55, to a pair of upstanding lugs 58 secured to one side of the upper end head I 9, the central part of this holddown bar being arranged to bear downwardly upon a pair of lugs 59 provided centrally on the cover 52. The free end of the holddown bar is shown as engageable with a cam lever 6I) mounted on the side of the Vupper end head I9 opposite from the hinge for the holddown lever. This cam lever, together withr its mounting, can be of any usual and well known construction to be brought into engagement with the free end of the holddown bar and force it downwardly to effect pressure sealing of the cover 52. As the details of this cam lever 69 and its mounting form no part of the present invention, it is not illustrated in detail.

Upon releasing the cam lever 60 the bifurcated holddownbar "54 can-be raised,` this lbar swinging around its pivots' 56 for this purpose. kTo facili# tate raising the cover 52 this cover is shown as connected to the. holddown bar so as to be lifted therewith. 'For this purpose, a .pair of links 6I are shown; each of which is shown as pivoted at'its upper end to one arm of the bifurcated holddown bar 54 and at its lower end to the corresponding lug 59 upon the cover. The pivotal connections of these links are preferably suiiiciently loose as not to interfere with direct engagement between the holddown bar 54 and the lugs 59 of the cover 52 in pressing the cover downwardly against its seat but insure lifting of the cover 52 when the holddown bar 54 is released from the cam lever 60 and manually elevated. Y

-,The domed shape of the cover 52 and its rim form, in combination with` the disk 49 of filterv paper, provide a filtering chamber 62 into which the distilled lubricating oil and the refining solids entrained therein are drawn by vacuum as hereinafter described.'

lThe batch of used lubricating oil to be rene'd is introduced through an elbow fitting 65 having a threaded stem extending through the upper end head I9 and to the lower end of whichV an elbow 66 is secured, this elbow being arranged in the upper part of the vaporchamber 3| andY connecting with the side wall 38 forming the preheating chamber 40 so as to discharge the used lubricating oil into this preheating chamber 40. In this chamber the batch 'of oil is preheated through heat derived from the finished or reflned oil in the chamber 36. After the incoming charge of used lubricating oil has been so preheated, the operator lifts the lever 68 shown in Fig. 5 which is connected by a rod 69 extending through the upper end head I9 and the lower end of which connects with a valve head 10 within the valve housing 1I of a dump valve indicated generally at 12. The manual valve lever 68 has its lower part formed to provide a cam surface 13 which engages a plate 14 on the head I9 and the pivotal connection between this hand lever and the rod 60 is such that when the hand lever 68 is rotated to the generally upright position shown in Fig. 5, the cam surface 13 cooperates to lift the rod 6 9. housing 1I of the dump valve 12 has an inlet conduit 15 communicating with the preheating chamber 40 formed between the sump 25 and the shell 38 and its outlet 16 is surrounded by a valve seat 18 against which the valve head 10 seats when the handle 68 is brought to its horizontal position. It will therefore be seen that upon lifting the manual dump valve handle 68 thev valve head 10 is vremoved upwardly fromv its seat. 18p thereby to vpermitl th'e' chargefof` pre# heated'sed lubricating oil to 'now from thepre-v heating chamber 40 into the vapor chamber 3 I.

This charge of oil so dumped by manipulation.

ofthe dump valve lever 68 flows to the bottom 2I, 22 of this chamber. and thence into the distillation chamber 21 in the sump 25. The refining operation of the. present invention also involves the use of refining solids such as fullers earth which is mixed with the batch of preheated used lubricating oil so dumped itno thesump 25 by opening the dumpv valve12.` To( introduce the shown in Fig. 4. The upper open end of this Thev opened' the" dump valve 12`he` removes .the l'cover 80? and `pours `a vcharge Vof fullers earth' intoV the tubef19. .Thisy charge of fullers earth flows down through thetube 19and drops into the distillac' tion 'chamber 21 formediby .the sump 25 to join the batch of preheated used4 lubricating oil contained therein.

VYIn this distillation chamber 21 the oil, together with the refining solids, is subjected to the heatlofingaction ofthe electrical heating elements 34 contained within the exterior pockets of the hollow radially 'projecting fins 32 of the wall 26 of this chamber. -This heating is continued until thecharge of oil is brought up to a temperature which drives off the undesirable lighter fractions of 'the used lubricating oil and for this purpose the maximum temperature of the oil within the sump "25 is under thermostatic control. This control is derived -from two -thermostats imme'rsed'in the oil within the sump`25, one of these thermostats designated at 8l being set to operate at`435 F., and theother of these thermostats, designated-at 82- beingset to operate at 450 F. These thermostats operate through" the electrical ''circu`it hereinafter described.'

While the batches of used lubricating oil and refining solids are so being heated within the distillation chamber 21 they are subjected to agitation andaeration to provide improved heat transfer 3041iand more rapid heating of the oil as well as to accelerate the release'of the 'lighter fractions as vapor from the lubricating oil.` This agitation also operates to keep the fullers earth or other a refining solids in suspension and-to insure inti- `^-mate contact between the used lubricating oil and the fullers earth.` To provide this agitation and aeration a goose neck tube 83 has its open outlet end disposed in the bottom of the sump 2-5 and its' arching portionarranged in thevvapor ifspace 3|, with its other. end extending through the bottom-2|, 22 of this vapor space and the horizontal semicircular plateV I4 of the shell and connectingwith the outlet of apump 84. This pump isV suitably mounted on the base plate l0 .1g-- alpngside the diametrically extending Vertical platev I2l and is driven by anv electric motor 85 which isfactuated as hereinafter described. The lighter fractions 'driven off of the batch of used lubricating =oil contained within the sump 25 by 5g`f-thecombined action of the heating elements 34 and the agitation provided by the discharge of compressed air from the gooseneck tube 83 rise into the vapor space 3| and are exhausted there,- from by an exhaust fan 86. As best shown in 555mg. 6 the inlet 88 for this exhaust fan extends through the inner and outer cylindrical shells 2li and I 8 so as to communicate with the vapor space 3l 'andthe'outlet'of this 'fanis arranged 'td dis-f charge'itheivapors to the atmosphere. This exe'v haust fln is driven by an electric motor 89er# earth, together with the remaining impurities.A For this purpose a transfer tube 90 has itsrlower t end arranged in the bottom of the sumpr 25 and extends upwardly therefrom and is secured ina bore; 9fextending through" the head [9; asy bestishown' injFig, 5l 'In'the upper end ofthis boreis fitted a pipe 92 which`c`nne;cts with a'rotary' slipjoint 934 arranged coaxially with the -hinge pivotsV 7". nects with a pipe 94 which communicates with a horizontal bore 95 through the cover 52, the'inner open end of this bore being arranged to discharge the oil centrally into the filtering chamber 62 on top of the disk 49 of lte'r paper which is clamped in position by this cover.

The vacuum for inducing the flow of oil from the sump 25 up through the transfer tube 90, slip joint 93, pipe 94 and conduit 95 is applied to the nished oil chamber 36 by the pump 84. For this purpose a suction line 96 is provided, the inlet end of which, as best shown in Fig. 4, extends through the upper end head I9 into the nished oil chamber 36 and thence downwardly through the vapor space 3 I. This inlet of the suction line 96 can be protected by an overhanging cap 91 of any suitable form and from the vapor space 3| this vacuum line 96 extends downwardly through the bottom 2|, 22 of this vapor space and through the semicircular horizontal plate |4 to the exterior of the casing. The lower end of this suotion line 96, as best shown in Figs. l and 9 connects with one inlet 98 of a three way solenoid valve 99. The other inlet of the three way solenoid valve is open to the atmosphere. The outlet |0| of this three Way solenoid valve connects, through a suction line |02, with the inlet of the pump 84. In the de-energize-d condition of the three way solenoid valve 99 the inlet of the pump is connected, through the line |02, with the valve inlet 98 connecting with the suction line 96 and under these conditions a vacuum is applied, through this line 96, to the iinished oil chamber 36. This vacuum, through the disk 49 of the filter paper, serves to draw the charge of oil and fullers earth contained within the sump 25 up through the line 90, slip joint 93, and conduit 95 through the cover 52 to be discharged into the filtering chamber 62 on top of the disk 49 of filter paper. The fullers earth, together with the remaining impurities within the batch of oil, is retained on this disk of filter paper. The puriiied oil passes through the filter paper into the finished oil chamber 36. After the refined oil within the chamber 36 has been utilized to preheat an incoming charge of used lubricating oil, the operator opens the discharge valve |03 shown in Fig. 4. This discharge valve is arranged in a pipe |94 extending through the'inner and outer shells 20, I8 of the casing and connecting through an elbow |05 with a discharge orifice |96 through the bottoms 39 of the shells 35 and 38.

In the energized condition of the three way solenoid valve 99 the inlet of the pump is connected, through the line |02, with the valve inlet |00, this valve inlet |99 being open to the atmosphere.

To relieve the vacuum in the filtering chamber 62 and finished oil chamber 36, and thereby permit the cover 52 to be raised, a vent valve |08 is provided in the cover 52.

Thev apparatus is semi-automatic in its operation and for this purpose is provided with the electrical control circuit shown in Fig. 9. In this circuit the numeral |09 represents one side of a main power line and the numeral II@ represents the other side of this main power line, this main power line being under control of a line switch III. The fan motor 99 is connected directly across the main power line |99, H0 so as to be energized when this line switch III is closed. Each cycle of operation is initiated by a manual start button switch |52 which is connected to the side |99 ofthe main power line y and connects with a line ||3 leading to the winding I4 of'a heater circuit relay ||5. The other end of this winding ||4 is connected by a line I|6 with a normally closed switch IIB actuated by the 435 thermostat 6 I. The other terminal of this switch ||8 connects with a normally closed switch II9 actuated by the 450 thermostat 82. Theother terminal of this switch IIS is connected with the other side |I0 of the main power line.

The relay ||5 is provided with two normally open armatures |29 and |2|.' When the relay is energized the armature |20 closes a circuit from the side I 99 of the main power line through lines |22 and |23 through one group of the heating elements 34 to the other side ||0 of the main power line. Similarly, when the relay ||5 is energized the armature |2| closes the circuit from the side |09 of the main power line through lines |24 and |25 and another group of the heating elements 34 to the other side ||0 of the main power line.

The winding |28 of the solenoid valve 99 is connected to parallel with the winding ||4 of the heater circuit relay ||5 and for this purpose one end of the solenoid valve winding |28 is connected by a line |29 to the line ||3 and the other end of this winding |29 is connected by a line |39 with the line H9. It will therefore be seen that the heater circuit relay ||5 and the solenoid valve 99 are energized and deenergized simultaneously.

The numeral |35 represents a pump motor and holding relay, one end or" the winding |36 of which is connected by a line |39 with the wire ||3 to the winding ||4 of the relay ||5 and the other end of which winding |39 is oonnected by a line |39 with the other side |||l of the main power line. This relay |35 is provided with two normally open armatures |49 and |45.

The armature |49 of the relay |35 is con nected by a line |42 with the side |99 of the main power line and is drawn into engagement with a fixed contact of a line |43 connecting with the line |44 of the pump motor |95. The other terminal of the motor is connected to the other side ||9 of the main power line. This armature I 49 of the relay |35 is bypassed by a manual switch |45 which, when closed, connects the side |99 of the main power line through a line |46 with the line |44 of the pump mo-v tor 85.

The armature I-'iI of thev relay |95 forms a part of the holding or locking circuitv VVfor the relays I|5 and |35 and the solenoid-valve 99 and for this purpose'is drawninto engagement with a fixed contact connected with the line |39. This armature is connected with the fixed Contact |48 of a switch indicated generally at |49. The movable contact |50 of this switch is connected with the side |99 of the main power line and is also arrangedto engage a fixed contact |'5|. This fixed contact I5| is connected with the line |44 of the pump motor 95. The movable contact |59 oi the switch E49 is actuated by a controller |52 which is responsive to the vacuum Within the finished oil chamber 39. When atmospheric pressure obtains within the finished oil chamber 36, the vacuum controller |52 actuates the movable Contact |59 of the switch'r |49 to engage the fixed Contact |48. When the vacuum inth'e nished oil chamber 36 is built up to a predetermined Value, the vacuum controller |52 actuates the movable contact |59 of the switch |49 to engage the fixed contact |5I.

n the following description of the operation of the apparatus for refining .used lubricating oil it will be assumed that the main switch I|| is closed so that the motor 89 of the exhaust fan or blower 86 is operating to exhaust any vapors developing in the vaporV chamber 3| of the still, this exhaust fan operating continuously and so withdrawing vapors from the vapor chamber 3| through its inlet 88 communicating therewith. It will also be assumed that a charge of y oil has been refined and is retained in the chamber 36 of the refined oil shell v35.l This oil has been distilled and hence is yat high temperature, this heat being available for preheatingA the charge of used lubricating oil. This charge of used lubricating oil of, say, several gallons, is admitted through the inlet pipeV 65 and iiows into the preheating chamber 4|) formed between the shells 35 and 38 and hence is preheated through heat derived from the charge of hot refined oil in the refined oil chamber 36, this heat exchange being accelerated by the fins 4|. After the desired preheating has taken place the charge of used oil to be refined is dumped from the preheating chamber 40 and thedischarge valve |93 is opened to discharge the finished oil from the refined oil chamber 36 following which this discharge valve |83 is closed to permit vacuum to be built up in this refined oil chamber St as hereinafter described.

Thisdumping vof the preheated oil from the preheating chamber 40 is effected by lifting the dump valve handle 68, this camming the rod B9 upwardly to lift the dump valve head 19 from its seat 18. Accordingly the preheated charge of oil to be refined can ilow from the preheating chamber 49 through the conduit 15 and through the dump valve 12, dropping` from its` outlet'19 to the frustoconical bottom 2 I of the vapor chamber 3| and flowing thence into the vapor distil lation chamber 21 of the sump 25.

The operator then momentarily closes the start button H2 and pours a charge of fullers earth into the batch of oil in the sump 25. This charge of fullers earth is admitted by lifting the `cover 89 at the upper open end of the vertical tube 19 and pouring the fullersearth therein. This `fullers earth flows downwthis tube 19 and drops therefrom dir ectlyy into the charge of oil contained in the sump 25. This momentary closing ofthe Vstart button I2 starts the cycle of operation by energizing the heater circuit relay ||5; the three way solenoid valve 99; and the pump motor'relay |35 which also serves as a holdingrelay. i The heater circuit relay is energized Afrom the side |89 of the main power line, closed start button I2, line I3, winding I I4 of this relay, line IIE and closed contacts I I8 and ||9 of the thermostats 8| and82v to the other side Ill) of the main power line since the winding |28 of the vsolenoid valve 99 is in parallel withV the winding of this relay II5, this solenoid valve is likewise energized. 4The pump motor relay |35 is energized" from the side |09 of the main power line, closed start buttonI l2, lines ||3 and |38 and Awinding |36 4through the line |39 to the other side I I ,ofthe main power line.'

The energization of the`relay|35 serves both to energize the pump motor 8,5 and to lcckor hold the heater circuit relay I Ii and the solenoid valve 99 in an energized condition.y .This locking orestablishing a 'circuit'froin the side' 'I9"'o`f the' main Ipower line, closed switch |49 of the vacuum controller |52 and closed armature |4I' to the line |38. Since this line |38 connects with the winding |36 of the relay |35 this relay is held energized until broken by the movable contact |59 of the switch |49 and since this line I 38 connects, through the line `I I3, with the winding I I4 of the relay I I5 this relay is held energized until broken by either of the switches I I8 or H9. Since the winding |28 of the solenoid valve 99 is in parallel with the winding ||4 of the relay ||5 this solenoid valve 99 is energized during this continued energization of the relay II5.

Energization of the pump motor relay |35 pulls up its armature |48 to establish a circuit from the side |39v of the main power line through line |42, closed armature `|43 of this relay |35, line |43, |44 and ypump motor 85 to the other side IID of the main power line. This starts operation of the pump 84 and since at this time the solenoid valve 99 is energized its outlet |92 is connected to atmosphere through the inlet |99. In consequence, the pump 84 draws atmospheric air from the inlet |00 of the solenoid valve 99 through this valve and its outlet IUI and through the line |92 connecting with the inlet of the pum-p. This air is discharged by pump through the line 83 and escapes from the open end thereof arranged at the bottom of the distillation chamber 21. Since this distillation chamber is lled with a charge of the used lubricating oil containing fullers earth, this escaping compressed air serves to agitate the charge of oil and to keep the fullers earth in suspension and in intimate moving contact with the oil so as to adsorb the impurities therefrom in a minimum .length of time. Further, as this batch of oil within the distillation chamber 21 is heated to -distil the lighter fractions therefrom, the compressed air escaping from the submerged end of the tube 83 Serves to aerate the body of oil and aid the separation of the lighter fractions as vapor therefrom. l

This heat for raising the temperature of the body of used lubricating oil within the distillation chamber 21.to the proper'- distillation temperature, is provided through the energization of the heater circuit relay II5.v Since at this time this heater circuit relay isenergized its normally open armatures |29 and|2| aredrawn up to close circuits through the two groups of heating coils 34. These heating coils are arranged in the external recesses provided in the wall of the sump 215 and hence theheatdeveloped by these elements is transmitted to the bodyof used lubricating oil contained within this sum-p.

The rising temperature and compressed air agitation oi the charge of used lubricating oil within the distillation chamber 21 of the sump 25 serves to drive 01T the lighter fractions, these escaping as vapor into the vapor space 3|. Since this vapor space is continuously being exhausted by the exhaust fan 8G, these vapors'are continuously I ning discharged to the atmosphere. This heating of the charge of usedlubricating oil in the sump 25 continues until the temperature of this charge of oil reaches 4357 F. When this temperature is reached the thermostat 8| immersed in this body ofoil opens the switch IIB. Opening the switch II8A opens the circuit through the winding of the heater circuit relay H5l and hence releases its Atwo armatures |29 andu 2| totheir normally open position. This opens the electrical circuit through the heater elements 34 andhence the heating of the chargejof'usedi lubricating oil in the sump 25 is discontinuedwhen its temperature reaches 435 F. This opening of the switch H8 by the thermostat 8| also deenergizes the solenoid valve 99 inasmuch as the winding of this solenoid lvalve is in parallel with the winding H4 of the heater circuit relay H5. This causes the solenoid valve to assume the position s hown in Fig. 9, in which its atmospheric air inlet |55 is cut off and instead its outlet lill is connected with its inlet 98. With the solenoid Valve 99 so deenergized air is withdrawn from the finished oil chamber so as to build up a vacuum therein, this air passing from this finished oil chamber 35 through the vacuum line 96, .inlet of the solenoid valve 93, outlet Iiii and line $32 to the inlet of the pump 34. from the outlet of this pump 85 through the goose neck tube 53 to escape into and agitate the body of used lubricating oil and fullers earth contained within the sump 25..

As the vacuum in the finished oil chamber 35 builds up, the charge, of used lubricatingr oil and fullers earth within the distillation chamber 2l in the sump is sucked out of this sump and brought to the ltering chamber 52 for nltration. This oil iiows upwardly through the tubo Si?, bore 5|, pipe 52, rotary slip joint 53, horizontal pipe 9d and horizontal bore 55 into the ltering chamber 52 formed by the cover 52. This stream of used lubricating oil and fullers earth so sucked up escapes from the open end of the horizontal The air so withdrawn is discharged bore 95 in the cover 52 and spreads over the disk i9 of lter paper which is clamped in place over the finished oil chamber by the cover 52. The fullers earth, together with the impurities absorbed therein, are retained within the cover 52 by the disk 4S of filter paper. The distilled and filtered oil passes through this disk 45 of filter paper and fiows down into the finished cil chamber 36.

When the vacuum within the finished oil chamber has been reduced to a predetermined low value by the pump 84, this following the transfer of the entire charge of used lubricating oil from the sump 25 to the upper part of the apparatus, the vacuum controller |52, which is responsive to the vacuum in the finished oil chamber 35, actuates the switch |419 to move its movable contact |55 out of engagement with the fixed contact |48 and into engagement with the fixed contact |5|.

Breaking this circuit between the movable contact 5G and the fixed contact |48 breaks the circuit through the winding |36 of the relay |35, thereby deenergizing this relay and placing it in the condition assumed at the start of the cycle of operation. At the same time, the operation of the motor 85 of the pump Sli is continued inasmuch as the movable contact |53 is brought into engagement with the fixed contact |5| thereby to supply current from the side |59 of the main power line, movable contact |55 of the switch |49, fixed contact |5| and pump motor line H4 and `pump motor 85 to the other side Hi) of the main power line.

The operator then breaks the vacuum within the filtering chamber 52 and finished oil chamber 36 by opening the vent valve |58 in the top of the cover 52. Breaking this vacuum causes the vacuum controller |52 to move the movable contact |50 of the switch |49 back into engagement with the fixed contact |48, thereof, thereby to restore this switch to the conditi n assumedat f the start of the cycle of operation eakinggthe l vacuum within the finished 011 chanter-'et permits the cover 52 to .be opened for the'pfurp of removing the disk 49 oflter paper, together? the cover 52.

l2 with the filtrate thereon, and replace it with fresh' disk of filter paper. To so lift the cover 52, the operator lifts the lever 65, thereby to uncouple the free end of the holddown bar 55. The operator, through the handles 55 on this holddown bar then lifts the same, this holddown bar swinging about the hinge pivots 56. vSo lifting this hold-.down bar 54 also lifts the cover 52 inasmuch as this cover is centrally connected to this holdj; down bar by the links 6|.

With the cover open the operator removes the disk i9 of lter paper from the screen i5 and throws the same away. He then places a fresh disk of filter paper 49 on this screen and `with its margin extending over the seat 5| provided around the opening which receives the cover 52. Accordingly, when the operator lowers the holddown bar 55 the angular rim of the cover 52 is brought itno clamping engagement with the margin of the fresh filter paper 49 and firmly clamps it against the upper end head i5. This clamping engagement is then maintained by forcing the lever 55 downwardly thereby to cam the holddown bar 54 downwardly and eect a rm seal of The operator has then made a complete cycle of operation and admits a fresh charge vof used lubricating oil through the inlet line as previously descri-b-ed. Before vacuum is again applied to the finished oil chamber 35 the operator, of course, closes the vent valve |58.

Referring particularly to the electrical wiring diagram, Fig. 9, the second or 450 thermostat 82 is purely a safety device so that if the 435 thermostatl should fail to operate, the 450 thermostat will open the circuit. Also, the manual switch |45 around the relay |35 is provided so that the pump motor can be operated manually at any time desired.

From the foregoing it will be seen that the present invention provides for the simple and effective agitation and aeration of the mixture of used lubricating oil and refining solids, such as fullers earth, being distilled and also provides a simple and reliable electrical control for automatically cycling each operation of the apparatus.

We claim:

1. In apparatus for refining used lubricating oil having a heated distillation `chamber adapted to receive a charge of the used oil to be refined and a charge of refining solids, an overhead enclosed filtering chamber, and a transfer line having its inlet communicating with the bottom of said distillation chamber and its outlet communicating with the upper part of said overhead filtering chamber,the combination therewith of apparatus agiitating Said charges in said distillation chamber and transferring said charges from said distillation chamber to said filterling chamber, comprising a pump, an outlet line for said pump and discharging into the bottom of said distillation chamber to agitate and aerate said charges therein, a three-way solenoid valve arranged when de-energized to connect one of its inlets with its outlet and when energized to connect the other of its inlets with its outlet, a line connecting said outlet of said solenoid v-alve with the inletv of said pump, a conduit connecting said one of said valve inlets with said enclosed filtering chamber to reduce the pressure in said enclosed filtering chamber below the pressure of said distillation chamber and thereby draw` said charges of used lubricating oil and reningsolids from said distillation chamber up said transfer line and into-said filtering chamber, and a thermostat having its sensitive parts in heat exchange relatien, withV said cnarges 1n said distillation lchamber and arranged tode-'energize said-threeway solenoid valve.

2. In'apparatus for refining used lubricating oil having a distillation chamber heated by electrical heating elements and adapted to receive a charge of the usedoil to 'be refined and a charge ,ofrening solids, an overheadltering chamber,

and a transfer line having its inlet communicating with the bottom of saiddis'till'ation chamber and its outlet communicating with the upper part of said overhead filtering chamber, the combinay tion therewith of apparatus agitating said-charges in said distillation chamberytransferring said charges from said distillationchamber tosaid filtering chamber and rendering'said electrical heating elementsinoperalvacomprising apump, a Solenoid valve arranged. when;de-energized@ cpnnect the yinlet Qfsaidpump with said enclosed filtering chamber to reduce the pressure in said enclosed filtering chamber below the pressure of said distillation chamber and thereby draw said charges of used lubricating oil and refining solids from said distillation chamber up said transfer line and into said ltering chamber and, when energized, to connect the inlet of said pump with the atmosphere, a switch in series with said heating elements, and a thermostat having its sensitive parts in heat exchange relation with said charges insaid distillation chamber and arranged to open said switch and to de-energize said solenoid valve means.

3. In apparatus for refining used lubricating oil having a distillation chamber heated by electrical heating elements and adapted to receive a charge of the used oil to be rened and a charge of refining solids, an overhead filtering chamber, and a liquid transfer line having its inlet communicating with the bottom of said distillation chamber and its outlet communicating with the upper part of said overhead filtering chamber, the combination therewith of an electrical control apparatus for a cycle of operations initiated by closing a start switch and including agitating the said charges in said distillation chamber, transferring said charges to said filtering chamber, and restoring the control elements to their initial condition, comprising a pump, a motor driving said pump, a line connected with the outlet of said pump and discharging into the bottom of said distillation chamber to agitate and aerate the said charges therein, a start switch in series with the winding of a normally open relay and a normally closed thermostat switch, a thermostat having its sensitive parts in heat exchange relation with said charges in said distribution chamber and opening said thermostat switch in response to a rising temperature of the charges in said distillation chamber, a three-way solenoid valve in parallel with the winding of said relay and having its outlet connected with the inlet of said pump, a rst inlet connected with the atmosphere and a second inlet, said solenoid valve when energized connecting its outlet with said first inlet, a vacuum line connecting said second inlet with said filtering chamber to establish a vacuum therein and draw said charges from said distillation chamber, up through said transfer line and into said filtering chamber, and electric lines connecting said heating elements in series with the armature of said relay.

4. In apparatus for refining used lubricating oil having a distillation chamber heated by electrical heating elements and adapted to receive a charge ofthe used y oilwtov be refined anda charge of 4refining solids, anoverhead filtering chamber, and a liquid transferdine having its inlet communicating with the bottom -of said distillation' chambery and itsgoutlet communieating withthe upper partv of said; overhead ltering chamber, i the combination v.therewith of an electrical control apparatus fora cycleof operations initiated by closinga start switchand including transferring said charges to said ,filtering chamber and restoring the/control elements to their initial condition comprising a start switch 'in series v with the windings of a normally open relay'and a normally closed thermostat switch a thermostathaving its sensitive parts in heat exchangerelation with saidcharges -in said distribution chamber and opening said thermostat switch in'responseto aA rising tem.- perature of said charges in said distillation chamber, a pump, an electrical motor actuating said pump, a solenoid valve in parallel with the winding of said relay and having its outlet connected with the inlet of said pump, a vacuum line connecting an inlet of said solenoid valve with said filtering chamber to establish a vacuum therein and draw said charges from said distillation chamber, up through said transfer line and into said ltering chamber, said solenoid valve, when de-energized, connecting its outlet with said inlet, electric lines connecting said heating elements in series with the armature of said relay. a normally open holding relay having its winding in series with said start switch and in parallel with sad first relay and thermostat switch and its armature in parallel with said start switch in series with the winding of said holding relay and in series with the winding of said first relay and thermostat switch and said holding relay having a second normally open armature in series with said pump motor.

5. In apparatus for refining used lubricating oil having a distillation chamber heated by electrical heating elements and adapted to receive a charge of the used oil to be refined and a charge of rening solids, an overhead filtering chamber, a liquid transfer line having its inlet communicating with the bottom of said distillation chamber and its outlet communieating with the upper part of said overhead ltering chamber, the combination therewith of an electrical control apparatus for a cycle of operations initiated by closing a start switch and including transferring said charges to said filtering chamber and restoring the control elements to their initial condition comprising a start switch in series with the winding of a normally open relay and a normally closed thermostat switch, a thermostat having its sensitive parts in heat exchange relation with said charges in said distribution chamber and opening said thermostat switch in response to a rising temperature of said charges in said distillation chamber, a pump, an electrical motor actuating said pump, a solenoid valve in parallel with the winding of said relay and having its outlet connected with the inlet of said pump, a vacuum line connecting an inlet of said solenoid valve with said filtering chamber to establish a vacuum therein and draw said charges from said distillation chamber, up through said transfer linc and into said iiltering chamber, said solenoid valve, when de-energized, connecting its outlet with said inlet, electric lines connecting said heating elements in series with the armature of said relay, a normally open holding relay havrsaid holding relay and in series with the winding of said rs't relay and thermostat switch, saidl holding relay having a second normally open armature in series with said pump motor, a vacuum switch having a movable Contact congaging a xed Contact placing said vacuum switch in series with said iii-st armature of said holding relay and having a, fixed contact engageable with said movable contact and connected to place said vacuum switch directly in 1,

series with said pump motor, and a vacuum controller arranged to move said movable contactv of said vacuum switch from engagement *16 with said. first xed Contact` into engagement with said second xed Contactin rsponseto a high vacuum in said ltering chan'bel".4 v`

CARL I. MILLER. ALBERT MILLER.

REFERENCES CITED The following references are of record in the file of this :patent: nected to one side of said llne and normally enm Y UNITED STATES PATENTS"l y Number Name v l Date 930,989 Richards Aug. 10, l1909 1,185,944 Schley June 6, 1916 1,919,655 Hoffman et al July 25, 1933 2,161,964 La Brecque June 13, 1939 2,345,697 Boyce Apr. 4, 1944 2,425,377- La Brecque Aug. l2, 1947 2,440,680 Gerin May 4, 1948 

1. IN APPARATUS FOR REFINING USED LUBRICATING OIL HAVING A HEATED DISTILLATION CHAMBER ADAPTED TO RECEIVE A CHARGE OF THE USED OIL TO BE REFINED AND A CHARGE OF REFINING SOLIDS, AN OVERHEAD ENCLOSED FILTERING CHAMBER, AND A TRANSFER LINE HAVING ITS INLET COMMUNICATING WITH THE BOTTOM OF SAID DISTILLATION CHAMBER AND ITS OUTLET COMMUNICATING WITH THE UPPER PART OF SAID OVERHEAD FILTERING CHAMBER, THE COMBINATION THEREWTITH OF APPARATUS AGITATING SAID CHARGES IN SAID DISTILLATION CHAMBER AND TRANSFERRING SAID CHARGES FROM SAID DISTILLATION CHAMBER TO SAID FILTERING CHAMBER, COMPRISING A PUMP, AN OUTLET LINE FOR SAID PUMP AND DISCHARGING INTO THE BOTTOM OF SAID DISTILLATION CHAMBER TO AGITATE AND AERATE SAID CHARGES THEREIN, A THREE-WAY SOLENOID VALVE ARRANGED WHEN DE-ENERGIZED TO CONNECT ONE OF ITS 